CN112025230B

CN112025230B - Color latent image mold manufacturing method, mold, product manufacturing method and product

Info

Publication number: CN112025230B
Application number: CN202010719500.6A
Authority: CN
Inventors: 李挺; 杨东升; 陈顺波; 孙鹏飞
Original assignee: Great Wall Precision Metals Co ltd Of Cbpm; Chengdu Banknote Printing Co ltd
Current assignee: Great Wall Precision Metals Co ltd Of Cbpm; Chengdu Banknote Printing Co ltd
Priority date: 2020-07-23
Filing date: 2020-07-23
Publication date: 2021-10-15
Anticipated expiration: 2040-07-23
Also published as: CN112025230A

Abstract

The invention discloses a method for manufacturing a color latent image die, which comprises pattern design and an engraving plate, wherein the engraving plate comprises mechanical engraving and laser etching; the mechanical carving is to process a molding surface comprising elements and micro-points on the surface of a die in a mechanical carving mode according to the design content of a pattern, wherein the micro-points are positioned on the wall surface or around the bottom of the elements; the laser etching is to process a grating-like stripe structure consisting of a series of thin stripes with intervals close to the visible light wavelength on a micro point by laser; and processing similar grating stripe structures with the same structure on the micro-points corresponding to the same latent image pattern, and processing similar grating stripe structures with different structures on the micro-points corresponding to different latent image patterns. The product manufactured by the mould processed by the manufacturing method has colorful latent image patterns, and the anti-counterfeiting performance of the product is improved.

Description

Color latent image mold manufacturing method, mold, product manufacturing method and product

Technical Field

The invention relates to the technical field of dies, in particular to a method for manufacturing a color latent image die, a method for manufacturing a product and a product with a color latent image.

Background

On the one hand, the multicolor technology, also called "visual variable light design", is a technology for realizing that a specific area displays a specific structural color through the design of a micro-nano structure. The structural color is formed by white light dispersion caused by certain micro-nano structures in specific arrangement. Different from common pigment colors, the structural color has the advantages of fastness, environmental protection and the like, and is widely applied to gold and silver commemorative coins. 1/10 ounces of Guanshi Bodhisattva-Dii Guanyin released in 2000 is the first magic color coin released in China. The 'Renminbi representative meeting in the world of fifty years' gold and silver commemorative coin released in 2004 is the first magic color coin in China with completely independent intellectual property rights. The 'lucky culture' commemorative coin in recent years also applies the fantasy color technology.

On the other hand, the latent image anti-counterfeiting technology is one of the important technology for the anti-counterfeiting of the RMB, and the hidden denomination number on the fifth set of RMB is applied to the technology. The multiple latent image technology, for example "chinese invention patent with publication number CN100427320C discloses a method for making multiple latent images on metal surface layer, which comprises designing pattern and engraving plate, when designing pattern, firstly designing densely and uniformly distributed base points on metal surface layer, then decomposing the designed pattern of each latent image into tiny pattern points, the pattern points are smaller than the base points, one pattern point of each latent image falls on the same direction in the base points, at most one pattern point of each latent image falls in each base point, and there is no pattern point on the base points in the area where the latent image pattern does not cover the base points; when the template is carved, the base point is carved into a conical point, the pattern point is positioned on the conical surface or the bottom surface of the base point, and the template is carved; meanwhile, the Chinese invention patent also discloses an anti-counterfeiting product, wherein base points are densely and uniformly distributed on the surface layer of the product, the base points are conical points, and at most one pattern point is arranged on the base points in the same direction; the pattern points in the same direction form an anti-counterfeiting latent image pattern. In the technical scheme, the raised elements on the surface of the product are utilized to shield micro points around the elements, so that various pictures and texts are manufactured at the same part, and a viewer can observe different pictures and texts from different angles.

Based on the prior art, how to manufacture a product with the colorful visual effect and high anti-counterfeiting performance by utilizing the colorful technology and the multiple latent image technology becomes a difficult problem which needs to be overcome by a technical team.

Disclosure of Invention

In view of the problems and deficiencies in the prior art, one of the objectives of the present invention is to provide a method for manufacturing a color latent image mold, wherein a mold having a surface with a structure of primitive, micro-point and similar grating stripes is processed, and the mold can be used for manufacturing a product with a colorful visual effect and high anti-counterfeiting performance.

The method for manufacturing the color latent image die is specifically divided into two types according to whether the surface of a product is designed with a relief curved surface.

First, the surface of the product is not designed with a relief curved surface.

At the moment, a color latent image mould manufacturing method comprises pattern design and engraving plate, wherein during pattern design, a latent image pattern is designed firstly, then densely distributed primitives are designed, the designed latent image pattern is decomposed into a plurality of tiny microdots smaller than the primitives, all the microdots forming the same latent image pattern are designed in the same direction of the primitives, and the engraving plate comprises mechanical engraving and laser etching; the mechanical carving is to process a molding surface comprising elements and micro-points on the surface of a die in a mechanical carving mode according to the design content of a pattern, wherein the micro-points are positioned on the wall surface or around the bottom of the elements; the laser etching is to process a grating-like stripe structure consisting of a series of thin stripes with intervals close to the visible light wavelength on a micro point by laser; and processing similar grating stripe structures with the same structure on the micro-points corresponding to the same latent image pattern, and processing similar grating stripe structures with different structures on the micro-points corresponding to different latent image patterns.

Secondly, the surface of the product is designed with a relief curved surface.

At the moment, a color latent image mould manufacturing method comprises pattern design and engraving, wherein during the pattern design, a latent image pattern is designed firstly, then a relief curved surface with high and low relief is designed on a forming surface of the mould according to the imaging requirement of the latent image pattern, densely distributed primitives are designed on the relief curved surface, the designed latent image pattern is decomposed into a plurality of tiny microdots which are smaller than the primitives, and all the microdots forming the same latent image pattern are designed in the same direction of the primitives; the engraving plate comprises mechanical engraving and laser etching; the mechanical carving is to process a forming surface comprising a basic element, micro-points and a relief curved surface on the surface of the die in a mechanical carving mode, wherein the micro-points are positioned on the wall surface or around the bottom of the basic element; the laser etching is to process a grating-like stripe structure consisting of a series of thin stripes with intervals close to the visible light wavelength on a micro point by laser; and processing similar grating stripe structures with the same structure on the micro-points corresponding to the same latent image pattern, and processing similar grating stripe structures with different structures on the micro-points corresponding to different latent image patterns.

The two specific color latent image die manufacturing methods combine the unreal color technology in coin anti-counterfeiting and the multiple latent image technology in banknote anti-counterfeiting, realize color latent image anti-counterfeiting on the surfaces of the die and the products manufactured by die pressing of the die, and a viewer can observe different color pictures and texts from different angles.

The second object of the present invention is to provide a color latent image mold manufactured by the above method.

Specifically, the color latent image die comprises a die body, wherein the forming surface of the die body is simultaneously provided with elements concave on the surface, a plurality of tiny microdots decomposed by a latent image pattern and a grating-like stripe structure distributed on the microdots; the grating-like stripe structure consists of a series of fine stripes with the interval close to the wavelength of visible light; the micro-points are smaller than the elements, the micro-points are positioned on the wall surface or the periphery of the bottom of the elements, and all the micro-points forming the same heavy latent image pattern are designed in the same direction of the elements; moreover, the structures of the similar grating stripe structures on the micro-points corresponding to the same heavy latent image pattern are the same, and the structures of the similar grating stripe structures on the micro-points corresponding to different heavy latent image patterns are different.

Furthermore, the whole forming surface of the die is a plane with consistent height, or the whole forming surface of the die is a relief curved surface with undulation.

The third purpose of the invention is to provide a method for manufacturing a product with a color latent image, which comprises the steps of firstly preparing a novel color latent image die and a blank cake provided by the invention, mounting the color latent image die on a press, and pressing the blank cake by the press to manufacture the product.

Specifically, a precious metal product mould pressing manufacturing method is characterized in that a LIPSS microstructure is generated on the surface of a color latent image mould by means of a femtosecond laser direct etching technology to realize white light dispersion, and the structural color distribution and the divergent or spiral dynamic color conversion effect of a specific area are realized under the condition of white light irradiation and visual observation by combining the design of the LIPSS microstructure; then, combining with the latent image structure design, and utilizing the light and image shielding principle to manufacture a color latent image mold with a color latent image; and finally, transferring the color latent image to a noble metal product in a mould pressing mode to realize batch copying of the color latent image.

The fourth purpose of the invention is to provide a product with color latent images. According to whether the latent image on the surface of the product is a heavy latent image or a double or more multiple latent images, the product can be divided into a color latent image product with only one heavy latent image on the surface and a color latent image product with multiple latent images on the surface.

The product is a noble metal foil product or a noble metal seal product.

The product is made of any one or more of gold, silver, niobium, platinum and nickel.

The product is any one or more of commemorative coins, commemorative medals, commemorative strips, bottle caps, bank cards, tickets, labels and anti-counterfeiting paper.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the invention provides a method for manufacturing a color latent image mould.A grating stripe structure capable of carrying out color separation on white light is processed on a mould forming surface by laser, and a mould for processing a color latent image product is manufactured by combining a latent image structure applying a light and image shielding principle;

(2) the surface of the series of products with the color latent images provided by the invention is provided with the grating-like stripe structure serving as the color separator and the elements serving as the color selector, so that the multi-latent image imaging effect with color change is realized on the premise of not influencing the purity of the products, and the artistic expression and the anti-counterfeiting capability of the products are obviously improved.

Drawings

FIG. 1 is a flow chart of a method for manufacturing a product with color latent images.

Fig. 2 is a partially enlarged schematic view of a grating-like stripe structure.

FIG. 3 is a schematic diagram of the shape of the color selector element in the form of lines, triangular pyramids, and quadrangular pyramids; wherein, the outline structure of the element in FIG. 3a is linear; the outline structure of the element in FIG. 3b is a triangular pyramid; the cell outline structure in fig. 3c is of the quadrangular pyramid type.

FIG. 4 is a schematic diagram showing only one image when viewed at a fixed angle due to the shape and position relationship between the primitives and the micro-points.

Fig. 5 is a schematic diagram of the principle that white light is longitudinally reflected into light beams of different colors by a grating-like stripe structure, and then is shielded by a primitive to present visual effects of different colors in the visual field of an observer.

Fig. 6 is a schematic diagram of a principle that white light is reflected into different color beams at a plane angle by a grating-like stripe structure, and then is shielded by a primitive to present different color visual effects in a visual field of an observer.

FIG. 7 is a schematic diagram of the superposition of "long" and "city" double latent images.

FIG. 8 is a schematic view of the superposition of the quadruple latent images of long, city, gold and silver.

FIG. 9 is a "long" word consisting of a number of # 1 microdots.

FIG. 10 is a "city" word consisting of a number of # 2 microdots.

FIG. 11 shows a "gold" pattern consisting of a number of 3# microdots.

FIG. 12 is a "silver" word consisting of a number of # 4 microdots.

Detailed Description

For a better explanation of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail by way of examples with reference to the accompanying drawings.

Example 1:

the embodiment provides a method for manufacturing a color latent image mold, which is used for processing a mold with a molding surface having a structure of elements, micro-points and similar grating stripes, and can be used for manufacturing products with a colorful visual effect and high anti-counterfeiting performance.

First, the surface of the product is not designed with a relief curved surface.

At the moment, a color latent image mould manufacturing method comprises pattern design and engraving, wherein during the pattern design, a latent image pattern is designed firstly, then densely distributed primitives are designed, the designed latent image pattern is decomposed into a plurality of tiny microdots smaller than the primitives, and all the microdots forming the same latent image pattern are designed in the same direction of the primitives; the engraving plate comprises mechanical engraving and laser etching; the mechanical carving is to process a molding surface comprising elements and micro-points on the surface of a die in a mechanical carving mode according to the design content of a pattern, wherein the micro-points are positioned on the wall surface or around the bottom of the elements; the laser etching is to process a grating-like stripe structure consisting of a series of thin stripes with intervals close to the visible light wavelength on a micro point by laser; and processing similar grating stripe structures with the same structure on the micro-points corresponding to the same latent image pattern, and processing similar grating stripe structures with different structures on the micro-points corresponding to different latent image patterns.

Secondly, the surface of the product is designed with a relief curved surface.

The two specific methods for manufacturing the color latent image die combine the color illusion technology and the multiple latent image technology, and the processed die is the color latent image die.

The color latent image mould in the embodiment comprises a mould body, wherein the forming surface of the mould body is simultaneously provided with elements concave on the surface, a plurality of tiny microdots decomposed by a latent image pattern and a grating-like stripe structure distributed on the microdots; the micro-points are smaller than the elements, the micro-points are positioned on the wall surface or the periphery of the bottom of the elements, and all the micro-points forming the same heavy latent image pattern are designed in the same direction of the elements; the grating-like fringe structure consists of a series of thin fringes spaced close to the wavelength of visible light.

The product pressed by the mould has a color latent image pattern on the surface. The surface of the product is provided with elements protruding out of the surface, a plurality of fine micro-points decomposed by a latent image pattern and a grating-like stripe structure distributed on the surface of the product; the micro-points are smaller than the elements, the micro-points are positioned on the wall surface or the periphery of the bottom of the elements, and all the micro-points forming the same heavy latent image pattern are designed in the same direction of the elements; the grating-like fringe structure consists of a series of thin fringes spaced close to the wavelength of visible light.

The product pressed by the mould manufactured by the method realizes color latent image anti-counterfeiting, and a viewer can observe different color pictures and texts from different angles.

Example 2:

in this embodiment, on the basis of embodiment 1, a mirror polishing and/or ion plating process is added to the color latent image mold manufacturing method, that is, the engraving process includes mechanical engraving, mirror polishing, laser etching, and ion plating processes performed in sequence. Two procedures of mirror polishing and ion plating in the procedures are not necessary, and can be selected and matched according to actual conditions.

In this case, a method of manufacturing a product having a color latent image includes preparing a mold and a green compact, mounting the mold on a press, and pressing the green compact with the press to form the product. As shown in fig. 1, when preparing a mold, a pattern design is first performed and then a plate is engraved, and the engraving process includes mechanical engraving, mirror polishing, laser etching, and ion plating in sequence.

Design of pattern

The design of the pattern determines to realize the color latent image in a specific area according to the product design specification, and the carving processing file and the laser processing file are output according to the design requirement.

Specifically, when designing the pattern, firstly designing a latent image pattern, then designing a relief curved surface with high and low relief on a molding surface of a mold according to the imaging requirement of the latent image pattern, designing densely distributed primitives on the relief curved surface, then decomposing the designed latent image pattern into a plurality of tiny microdots smaller than the primitives, and designing all the microdots forming the same latent image pattern in the same direction of the primitives.

If the product is provided with a designed relief curved surface, after the latent image pattern is designed, the relief curved surface with high and low relief is designed on the forming surface of the mould according to the imaging requirement of the latent image pattern, the elements which are densely distributed are designed on the relief curved surface, the designed latent image pattern is decomposed into a plurality of tiny microdots which are smaller than the elements, and all the microdots forming the same latent image pattern are designed in the same direction of the elements.

If the relief curved surface is not designed on the product, after the latent image pattern is designed, the operation of designing the relief curved surface on the mold forming surface is omitted, the elements which are densely distributed and a plurality of tiny microdots which are smaller than the elements and are decomposed by the designed latent image pattern are directly designed on the mold forming surface according to the latent image pattern, and all the microdots forming the same heavy latent image pattern are required to be designed in the same direction of the elements.

Further, in the pattern design process, the design of the raster stripe-like structure as a color separator and the design of the primitive as a color selector need to be considered.

A. Design of color separator

A grating-like stripe structure as a color separator is a microstructure consisting of a series of fine stripes spaced close to the wavelength of visible light. The partially enlarged grating-like stripe structure is shown in fig. 2, where a is the width of the fine stripe and b is the pitch of the fine stripe. The distance between the thin stripes refers to the sum of the minimum gap between the adjacent thin stripes and the width of the thin stripe body. The shape of the fine stripe in the grating-like stripe structure is a straight line or a curve, namely the fine stripe is a straight line segment or a curve segment. Further, the fine stripes in the grating stripe-like structure are distributed at equal intervals.

The similar grating stripe structure is realized on the surface of a die by using a femtosecond laser firstly, and then is transferred to a blank cake through the die, and finally, the corresponding similar grating stripe structure is displayed on the surface of a product. By utilizing the principle of grating color separation, white light is separated into light beams with various colors such as red, orange, yellow, green, cyan, blue, purple and the like after being reflected by the grating-like stripe structure. The space between the similar grating stripes is adjustable, and the angle is adjustable. The smaller the distance is, the better the light splitting effect on white light is, and the larger the visual angle of each color light beam is; the slight change of the angle can realize different colors of different areas under the condition that the observation angle is not changed. This is the premise that the following color selector realizes accurate color control.

When designing the similar grating stripe structure, the angle, position and distribution of the similar grating stripe structure need to be designed according to design requirements. Especially when the product needs to display multiple latent images, the grating-like stripe structure is required to realize the distribution of a specific angle in a specific area. The minimum dimension of the fine stripe in the grating-like stripe structure as a color separator is 0.0005mm, and the design can disperse white light. The width a of the fine stripes is 0.0005mm-0.0007mm, and the distance b of the fine stripes is adjustable between 0.0005mm and 0.001 mm. The plurality of grating-like stripe structures are distributed continuously or discontinuously. Moreover, the plurality of grating-like stripe structures are distributed on the molding surface in the whole area or in the local area.

In the present embodiment, the scale represents a length unit of a three-dimensional space occupied by a certain structure (e.g., a cell, a thin stripe, etc.) in any dimension.

B. Design of color selector

The color selector has three-dimensional relief structure, and the shape of the color selector is linear, semi-spherical, conic, circular-jar, pyramid, cylinder or polygonal column.

As shown in fig. 3, the shape structure of the color selector element is a line shape, a triangular pyramid shape, or a quadrangular pyramid shape, and only one micro-dot is observed from each side. In fig. 3a, the outline structure of the element is linear, the left side is designed with yellow microdots (1 # microdots), and the right side is designed with red microdots (2 # microdots). In fig. 3b, the outline structure of the element is a triangular pyramid, and yellow microdots (1 # microdot), red microdots (2 # microdot) and green microdots (3 # microdot) are respectively designed in three directions corresponding to three bottom edges of the triangular pyramid when viewed in a clockwise direction. In fig. 3c, the outline structure of the cell is a quadrangular pyramid, and yellow microdots (1 # microdot), red microdots (2 # microdot), green microdots (3 # microdot), and blue microdots (4 # microdot) are respectively designed in four directions corresponding to four bottom sides of the quadrangular pyramid, viewed in the clockwise direction. If the image continues to be changed into an N pyramid type, N latent images can be realized theoretically.

As shown in fig. 4, when viewed at a fixed angle, other micro-points such as the surrounding yellow micro-point (1 # micro-point) are blocked by the convex color selector, thereby realizing the hiding effect. The viewer can only see the blue microdots (4 # microdots), so that the image and text consisting of a plurality of blue microdots (4 # microdots) are displayed.

The elements on the surface of the product are used as color selectors and are a series of convex structures which are distributed selectively, as shown in fig. 5, white light is divided into seven color beams of red, orange, yellow, green, cyan, blue and purple after being reflected by a similar grating stripe structure, the color numbers are respectively 1, 2, 3, 4, 5, 6 and 7, the color beams of No. 2 to No. 7 are blocked by the color selectors, and the red light beam (the code number is 1) enters the visual field of an observer, so that the red display of the point is realized. Similarly, if the color selector height is lowered, the color beams # 3-7 are blocked, and the red beam (# 1) and the orange beam (# 2) enter the viewer's field of view, a red + orange composite light display of the spot is achieved. Then the height of the color selector is reduced, the No. 4-No. 7 color light beams are blocked, the red light beam (No. 1), the orange light beam (No. 2) and the yellow light beam (No. 3) enter the visual field of an observer, and the red, orange and yellow composite light display of the point is realized. By analogy, the high selection of the color selector can achieve a wide-area color display from red to white.

Again from a planar perspective, as in fig. 6. As well as the height, the planar structure also acts as a barrier to the color light beam. The light beams with seven colors of red, orange, yellow, green, cyan, blue and purple are numbered as above. The No. 1-No. 6 color light beams are blocked by the blocking of the color selector, and the purple light beams (code number 7) enter the visual field of an observer, so that the purple display of the point is realized. By analogy, purple + blue + cyan can be realized. . . . . . That is, a wide-area color display from purple to white is realized.

As shown in table 1, the color selector realizes wide-area color display by integrating the height and plane functions of the color selector.

TABLE 1

Further, the planar dimension range of the element is adjustable from 0.01mm to 0.1 mm; the height of the element can be adjusted from 0.01mm to 0.1 mm.

Two, mechanical carving

The mechanical carving means that a forming surface comprising a basic element, micro-points and a relief curved surface is machined on the surface of a die in a mechanical carving mode, and the micro-points are positioned on the wall surface or around the bottom of the basic element. The mechanical carving has the advantages of high precision, quantifiable and adjustable color selector depth, gradient, sharp angle radian and the like. By selecting different carving knife shapes such as a spherical knife, a V-shaped knife and the like, the appearance, the size and the position of the element can be accurately controlled.

The basic elements on the die are concave on the surface of the die body, after the basic elements are transferred to the blank cake, the basic elements are convex on the surface of the blank cake, and the convex basic elements on the blank cake are used as color selectors, so that the sight of people is partially shielded, and only the micro points in a certain direction of the basic elements can be seen, but the micro points on the visual back surface cannot be seen.

The micro points are concave or convex, and if the micro points on the die body are concave, the micro points are correspondingly convex after being transferred to the blank cake; similarly, if the micro-point on the die body is convex, after being transferred to the blank cake, the micro-point is correspondingly concave.

The micro-points are in a hemispherical shape, a conical shape, a round-jar shape, a pyramid shape, a cylindrical shape or a polygonal prism shape.

Third, mirror polishing

The mirror polishing refers to polishing the whole molding surface. The micron-sized surface polishing is difficult to achieve by using a traditional mechanical polishing method, and in the embodiment, the whole forming surface, especially the relief curved surface, is polished by sputtering polishing, so that the micron-sized surface polishing is achieved.

Fourthly, laser etching

The laser etching refers to laser processing of a grating-like stripe structure consisting of a series of fine stripes with intervals close to the visible light wavelength on a molding surface. In this embodiment, a femtosecond laser may be used to fabricate a grating-like stripe structure based on the laser LIPSS technique, and stripe line width and stripe spacing may be adjusted by controlling laser output power, pulse number, scanning speed, frequency, and the like.

The shape of the fine stripe in the grating-like stripe structure is a straight line or a curve, namely the fine stripe is a straight line segment or a curve segment. The plurality of grating-like stripe structures are distributed continuously or discontinuously. The grating-like stripe structures are distributed on the molding surface in the whole area or in the local area.

Ion plating

The ion plating refers to plating the whole forming surface. When the mold is made of metal materials, the grating-like stripe structure serving as a specific microstructure is formed on the mold body, has the physical characteristics of the metal materials, and can be directly subjected to ion plating on the molding surface of the mold without influencing the effect of the metal materials. The coating film can obviously improve the surface hardness of the die, improve the printing resistance of the die and realize batch transfer of patterns.

Sixthly, coining

And (5) mounting the color latent image die on a press machine, and pressing the blank cake by the press machine to obtain the product.

The method adopts metal, especially noble metal, to manufacture foil or seal products with one or more color latent images on the surface. In order to keep the purities of gold and silver, the precious metal products on the current market can only express the hierarchical relationship between patterns through a bright surface and a sand surface, the expression form is single, and the high-level anti-counterfeiting effect is difficult to realize. The application of the color latent image technology on noble metal products brings colorful colors into the field of the noble metal products, so that the noble metal products enter the color era, the artistic expression of the products is greatly improved, the anti-counterfeiting capability is obviously improved, and a high wall is built in front of counterfeiters.

Usually, noble metals such as gold, silver, platinum, etc., or general metals such as niobium, nickel, etc., may be used, and alloy materials such as: including gold-silver based alloys, gold-platinum alloys, and the like. The gold-silver alloy herein refers to an alloy composed of gold and silver, and an alloy composed of a gold-silver alloy as a base and other components, and mainly includes a gold-silver alloy, a gold-silver-copper alloy, and a gold-silver-palladium alloy.

Products, on the other hand, include, but are not limited to, foil type, chapter bar type. The product can be a commemorative coin, a commemorative badge, a commemorative strip, a bottle cap, a bank card, a ticket, a label or anti-counterfeiting paper and the like.

Commemorative coins (also called commemorative coins) and anti-counterfeiting paper are taken as examples. The existing magic color technology on the coin adopts the combination of the traditional holography and the electroforming and the overturning, and the embodiment utilizes the laser direct engraving to realize the magic color effect; the multi-latent image technology on the existing anti-counterfeiting paper (such as a banknote) utilizes the shielding effect of the ink salient points, and the salient points of the noble metal body can be utilized to play the shielding effect in the embodiment.

The invention combines the magic color technology in coin anti-counterfeiting and the multiple latent image technology in banknote anti-counterfeiting, realizes the color latent image anti-counterfeiting on the surface of the noble metal mold and the noble metal product manufactured by the noble metal mold in a mold pressing way, and observers can observe different color images from different angles.

Selecting the line-shaped elements in fig. 3a, the product manufactured by the above-mentioned product manufacturing method exhibits a "long" and "city" double color latent image pattern, as shown in fig. 7.

The rectangular pyramid type elements in fig. 3c are selected to show quadruple colored latent image patterns of "long", "city", "gold" and "silver" on the product manufactured by the above-mentioned product manufacturing method, as shown in fig. 8. The single color patterns of the quadruple color latent image pattern are decomposed independently as shown in fig. 9, 10, 11 and 12.

FIG. 9 is a "long" word consisting of a number of # 1 microdots.

FIG. 10 is a "city" word consisting of a number of # 2 microdots.

FIG. 11 shows a "gold" pattern consisting of a number of 3# microdots.

FIG. 12 is a "silver" word consisting of a number of # 4 microdots.

It should be noted that the elements on the mold and the product correspond to each other: the elements on the mold are concave on the molding surface, the elements on the product are convex on the surface, and the outline of the outline structure of the elements on the mold and the product are consistent.

The micro-points on the mould and the product correspond to each other: the micro-points on the mould are concave on the molding surface, the micro-points on the product are convex on the surface, and the outline of the shape structure of the micro-points on the mould and the product are consistent. Of course, the micro-points on the mold can also be processed to be convex to the molding surface, and the micro-points on the surface of the product after transfer printing are concave to the surface of the product.

The similar grating stripe structures on the die and the product correspond to each other: the grating-like stripe structure on the mold is a straight line segment or a curve segment, and the grating-like stripe structure on the surface of the product presents a straight line segment or a curve segment which is opposite to the positions of the concave part and the convex part of the grating-like stripe structure on the molding surface of the mold.

Typically, the fine stripes in the grating-like stripe structure are equally spaced. All the micro-points of the same heavy latent image pattern are located at the same height relative to the reference plane of the die body. The micro-points in different directions of each element are located at the same height with respect to the reference plane of the mold body.

Further, the distance between adjacent thin stripes is 0.0005mm-0.0010 mm. The width of the thin stripes is 0.0005mm-0.0007 mm. The smallest planar dimension of the pinstripe is 0.1 mm. The longitudinal depth of the element is 0.01mm-0.1 mm; the planar dimension of the element is 0.01mm-0.1 mm.

Example 3:

the embodiment separately and specifically describes a color latent image mold, which comprises a mold body, wherein the molding surface of the mold body simultaneously has primitives concave on the surface, a plurality of tiny microdots decomposed by a latent image pattern and a grating-like stripe structure distributed on the microdots; the grating-like stripe structure consists of a series of fine stripes with the interval close to the wavelength of visible light; the micro-points are smaller than the elements, the micro-points are positioned on the wall surface or the periphery of the bottom of the elements, and all the micro-points forming the same heavy latent image pattern are designed in the same direction of the elements; moreover, the structures of the similar grating stripe structures on the micro-points corresponding to the same heavy latent image pattern are the same, and the structures of the similar grating stripe structures on the micro-points corresponding to different heavy latent image patterns are different.

Further, the structure of the grating-like stripe structure comprises the shape of the fine stripe, the width of the fine stripe, the distance between adjacent fine stripes and the inclination angle of the fine stripe.

Further, the shape of the fine stripe in the grating-stripe-like structure is a straight line or a curved line, that is, the fine stripe is a straight line segment or a curved line segment.

Further, the fine stripes in the grating stripe-like structure are distributed at equal intervals.

Further, the distance between adjacent thin stripes is 0.0005mm-0.0010 mm.

Further, the width of the thin stripe is 0.0005mm-0.0007 mm.

Further, the minimum planar dimension of the fine stripe is 0.1 mm.

Further, the longitudinal depth of the element is 0.01mm-0.1 mm; the planar dimension of the element is 0.01mm-0.1 mm.

Further, the element is in a line shape, a hemisphere shape, a cone shape, a round jar shape, a pyramid shape, a cylinder shape or a polygon prism shape.

Further, the micro-point is in a hemispherical shape, a conical shape, a round-jar shape, a pyramid shape, a cylindrical shape or a polygonal column shape.

Further, the micro-point is concave or convex.

Further, all the micro-points of the same heavy latent image pattern are located at the same height with respect to the reference plane of the mold body.

In the embodiment, a grating-like stripe structure is generated on the surface of the mold by means of a femtosecond laser direct etching technology. The grating-like stripe structure can also be described as a LIPSS microstructure, i.e. a laser induced periodic surface microstructure. The similar grating stripe structure is transferred to the surface of a product through a mould, and the convex part and the concave part of the similar grating stripe structure corresponding to the positions of the mould and the product are just opposite. The distance between the fine stripes in the grating-like stripe structure is close to the wavelength of visible light, so that the dispersion of white light can be realized, and the structural color distribution and various dynamic color conversion effects such as the divergence shape, the spiral shape and the like of a specific area can be realized under the condition of white light irradiation and naked eye observation. And then, by combining the shape and position relationship between the elements and the micro-points in the latent image design, the mold is manufactured by utilizing the light and shadow shielding principle. And finally, transferring the color latent images to noble metal products such as gold and silver in a mould pressing mode, thereby realizing the mass copying of the color latent images. The definition of the color latent image is that under the irradiation of white light, the product rotates at different angles, and hidden characters or patterns with different colors can be observed by naked eyes.

Example 4:

the embodiment separately specifies a product with a color latent image, wherein the surface of the product is provided with elements protruding out of the surface, a plurality of fine micro-points decomposed by a latent image pattern and a grating-like stripe structure distributed on the surface of the product; the grating-like stripe structure consists of a series of fine stripes with the interval close to the wavelength of visible light; the micro-points are smaller than the elements, the micro-points are positioned on the wall surface or the periphery of the bottom of the elements, and all the micro-points forming the same heavy latent image pattern are designed in the same direction of the elements; moreover, the structures of the similar grating stripe structures on the micro-points corresponding to the same heavy latent image pattern are the same, and the structures of the similar grating stripe structures on the micro-points corresponding to different heavy latent image patterns are different.

Further, the metal foil is a noble metal foil or a noble metal stamp.

Furthermore, the material of the product adopts any one metal or alloy of a plurality of metals of gold, silver, niobium, platinum and nickel.

Furthermore, the product is any one or more of commemorative coins, commemorative medals, commemorative strips, bottle caps, bank cards, tickets, labels and anti-counterfeiting paper.

Further, the distance between adjacent thin stripes is 0.0005mm-0.0010 mm.

Further, the width of the thin stripe is 0.0005mm-0.0007 mm.

Further, the minimum planar dimension of the fine stripe is 0.1 mm.

Further, the longitudinal depth of the element is 0.01mm-0.1 mm.

Further, the plane dimension of the element is 0.01mm-0.1 mm.

Further, the micro-point is concave or convex.

Furthermore, the surface of the product is a relief curved surface with high and low undulations, and the relief curved surface is provided with elements protruding from the surface, a plurality of fine micro-points decomposed by the latent image pattern and a grating-like stripe structure distributed on the surface of the product.

Furthermore, the color latent image pattern on the surface of the product is 2-9 weight.

The structural color, also called physical color, generated by the grating-like fringe structure is various colors generated by diffraction and interference of reflected light due to the nanometer-level fine structure. By means of the design of the nano optical structure, the reflected white light is modulated and color-separated, and different colors are displayed in different areas. The nano optical structure can be transferred to the surface of noble metal products such as gold and silver in a mould pressing mode, and color change is realized on the premise of not changing the components of the noble metal. This is to be distinguished from conventional pigment coloring.

On the other hand, the primitives and the microdots together form a latent image structure. The latent image structure design is to use the shielding principle, and uses three-dimensional structures such as raised points and lines as units, engraves micro-points at specific angles, and can be seen when observed at corresponding angles, but can not be seen at other angles, and uses the micro-points as starting points to realize the latent image structure of characters and patterns such as one, two, three, etc. One latent image structure corresponds to a heavy latent image pattern.

The same raster-like stripe structure is constructed on the micro-point of a certain heavy latent image structure, so that the color display of the latent image pattern corresponding to the latent image structure can be realized, and the raster-like stripe structures with different structures are designed for the micro-point of different latent image structures, so that different color hidden characters or patterns can be observed at multiple angles, namely, the observer can observe latent image patterns with different colors from different angles.

Example 5:

the embodiment discloses a noble metal product mould pressing manufacturing method based on embodiments 1-4, which is characterized in that LIPSS microstructures are generated on the surface of a color latent image mould by means of a femtosecond laser direct etching technology to realize white light dispersion, and structural color distribution and various dynamic color transformation effects such as divergence and spiral in a specific area are realized under the condition of white light irradiation and visual observation by combining the design of the LIPSS microstructures; then, combining with the latent image structure design, and utilizing the light and image shielding principle to manufacture a color latent image mold with a color latent image; and finally, transferring the color latent images to noble metal products such as gold and silver in a mould pressing mode to realize batch copying of the color latent images.

In order to better explain the technical solutions in the present embodiment, some technical terms in the technical solutions need to be explained.

1. The color latent image refers to different color hidden characters or patterns which can be observed by naked eyes when the die rotates at different angles under white light irradiation.

2. The LIPSS microstructure is also called a grating stripe structure, namely a laser-induced periodic surface microstructure, and is a nano-scale fine structure.

3. The latent image structure design is that by means of the shielding principle, raised points and lines are used as units, micro points are engraved at specific angles, and the micro points are visible at corresponding angles while other angles are invisible, so that one-fold, two-fold, three-fold and other latent image characters and patterns can be realized by using the micro points as starting points.

In the embodiment, the structural color generated by the LIPSS microstructure, also called as a physical color, is a color generated by diffraction and interference of reflected light due to the nano-scale microstructure. By means of the design of LIPSS microstructure, the reflection white light is modulated and color-separated, and different colors are displayed in different areas. The LIPSS microstructure can be transferred to the surface of noble metal products such as gold and silver in a mould pressing mode, and color change is realized on the premise of not changing the components of the noble metal. This is to be distinguished from conventional pigment coloring.

The same LIPSS micro-structure is constructed on the micro-point of a certain heavy latent image structure, so that the color display of the latent image pattern corresponding to the latent image structure can be realized, and the LIPSS micro-structures with different structures are designed for the micro-points of different latent image structures, so that different color hidden characters or patterns can be observed at multiple angles, namely, the latent image patterns with different colors can be observed by an observer from different angles. Moreover, the LIPSS microstructure can be transferred to noble metal products such as gold and silver by a mould pressing mode.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications and equivalent variations of the above embodiments according to the technical spirit of the present invention are included in the scope of the present invention.

Claims

1. A color latent image mould manufacturing method comprises pattern design and engraving plate, when the pattern design, firstly designing latent image pattern, then designing densely distributed elementary elements, then decomposing the designed latent image pattern into a plurality of tiny microdots smaller than the elementary elements, and designing all the microdots composing the same latent image pattern in the same direction of the elementary elements, characterized in that the engraving plate comprises mechanical engraving and laser etching; the mechanical carving is to process a molding surface comprising elements and micro-points on the surface of a die in a mechanical carving mode according to the design content of a pattern, wherein the micro-points are positioned on the wall surface or around the bottom of the elements; the laser etching is to process a grating-like stripe structure consisting of a series of thin stripes with intervals close to the visible light wavelength on a micro point by laser; and processing similar grating stripe structures with the same structure on the micro-points corresponding to the same latent image pattern, and processing similar grating stripe structures with different structures on the micro-points corresponding to different latent image patterns.

2. The method for manufacturing a color latent image mold according to claim 1, wherein the engraving plate is further polished by adding mirror polishing after mechanical engraving and before laser etching to polish the whole molding surface.

3. The method for manufacturing a color latent image mold according to claim 2, wherein the mirror polishing is sputter polishing.

4. The method as claimed in claim 1, wherein the engraving plate is further coated with an ion coating after the laser etching to coat the entire molding surface.

5. The method for manufacturing a color latent image mold according to any one of claims 1 to 4, wherein the laser etching is performed by using a laser LIPSS technology, and a grating-like stripe structure is etched by a femtosecond laser.

6. The method for manufacturing a color latent image mold according to claim 5, wherein the laser etching process adjusts the stripe width and the stripe interval of the raster stripe-like structure by controlling the laser output power, the number of pulses, the scanning speed and the frequency.

7. A color latent image mould manufacturing method comprises pattern design and engraving plate, when the pattern design, firstly designing latent image pattern, then designing relief curved surface with high and low relief on the forming surface of the mould according to the imaging requirement of the latent image pattern, designing densely distributed elements on the relief curved surface, then decomposing the designed latent image pattern into a plurality of tiny microdots smaller than the elements, and designing all microdots composing the same heavy latent image pattern in the same direction of the elements, characterized in that the engraving plate comprises mechanical engraving and laser etching; the mechanical carving is to process a forming surface comprising a basic element, micro-points and a relief curved surface on the surface of the die in a mechanical carving mode, wherein the micro-points are positioned on the wall surface or around the bottom of the basic element; the laser etching is to process a grating-like stripe structure consisting of a series of thin stripes with intervals close to the visible light wavelength on a micro point by laser; and processing similar grating stripe structures with the same structure on the micro-points corresponding to the same latent image pattern, and processing similar grating stripe structures with different structures on the micro-points corresponding to different latent image patterns.

8. A color latent image mould comprises a mould body and is characterized in that a forming surface of the mould body is simultaneously provided with elements concave on the surface, a plurality of tiny microdots decomposed by a latent image pattern and a grating-like stripe structure distributed on the microdots; the grating-like stripe structure consists of a series of fine stripes with the interval close to the wavelength of visible light; the micro-points are smaller than the elements, the micro-points are positioned on the wall surface or the periphery of the bottom of the elements, and all the micro-points forming the same heavy latent image pattern are designed in the same direction of the elements; moreover, the structures of the similar grating stripe structures on the micro-points corresponding to the same heavy latent image pattern are the same, and the structures of the similar grating stripe structures on the micro-points corresponding to different heavy latent image patterns are different.

9. The color latent image mold according to claim 8, wherein the configuration of the grating-like stripe structure comprises a shape of the fine stripe, a width of the fine stripe, a pitch between adjacent fine stripes, and an inclination angle of the fine stripe.

10. The color latent image mold according to claim 9, wherein the shape of the fine stripes in the grating-stripe-like structure is a straight line or a curved line, i.e. the fine stripes are straight line segments or curved line segments.

11. The color latent image mold according to claim 9, wherein the fine stripes in the grating-like stripe structure are equally spaced.

12. The color latent image mold according to claim 11, wherein the pitch between adjacent stripes is 0.0005mm to 0.0010 mm.

13. The color latent image mold according to claim 9, wherein the width of the fine stripe is 0.0005mm to 0.0007 mm.

14. The color latent image mold according to claim 9, wherein the minimum planar dimension of the fine streak is 0.0005 mm.

15. A color latent image mold according to any one of claims 9-14, wherein the elements have a longitudinal depth of 0.01mm-0.1 mm; the planar dimension of the element is 0.01mm-0.1 mm.

16. The color latent image mold according to claim 8, wherein the elements are linear, hemispherical, conical, prismatic, pyramidal, cylindrical or polygonal.

17. The color latent image mold according to claim 8, wherein the micro-dots are of a hemispherical shape, a conical shape, a round-jar shape, a pyramidal shape, a cylindrical shape, or a polygonal column shape.

18. The color latent image mold according to claim 8, wherein the micro-dots are concave or convex.

19. The color latent image mold according to claim 8, wherein all the micro-points of the same heavy latent image pattern are located at the same height with respect to the reference plane of the mold body.

20. A method for producing a product having a color latent image, comprising preparing the color latent image mold according to claim 8 and a cake, mounting the color latent image mold on a press, and pressing the cake by the press to produce the product.

21. A product with color latent image is characterized in that the surface of the product is provided with elements protruding out of the surface, a plurality of fine micro-points decomposed by a latent image pattern and a grating-like stripe structure distributed on the surface of the product; the grating-like stripe structure consists of a series of fine stripes with the interval close to the wavelength of visible light; the micro-points are smaller than the elements, the micro-points are positioned on the wall surface or the periphery of the bottom of the elements, and all the micro-points forming the same heavy latent image pattern are designed in the same direction of the elements; moreover, the structures of the similar grating stripe structures on the micro-points corresponding to the same heavy latent image pattern are the same, and the structures of the similar grating stripe structures on the micro-points corresponding to different heavy latent image patterns are different.

22. The product with color latent images according to claim 21, wherein the product is a noble metal foil-type or stamp-strip-type product.

23. The product with color latent images according to claim 21, wherein the material of the product is any one or more of gold, silver, niobium, platinum and nickel.

24. The product with color latent image according to claim 21, wherein the product is any one or more of a commemorative coin, a medal, a commemorative bar, a bottle cap, a bank card, a ticket, a label, and a security paper.

25. The product with color latent image according to claim 21, wherein the configuration of the grating-like stripe structure comprises the shape of the fine stripe, the width of the fine stripe, the pitch between adjacent fine stripes, and the tilt angle of the fine stripe.

26. The product with color latent image according to claim 21, wherein the shape of the fine stripe in the grating-like stripe structure is a straight line or a curved line, i.e. the fine stripe is a straight line segment or a curved line segment.

27. The product with color latent images of claim 21, wherein the fine stripes in the grating-like stripe structure are equally spaced.

28. A product having a latent colour image according to claim 27, wherein the spacing between adjacent stripes is in the range of 0.0005mm to 0.0010 mm.

29. The product with color latent images of claim 21, wherein the width of the pinstripes is 0.0005mm to 0.0007 mm.

30. A product with a color latent image according to claim 21, wherein the minimum planar dimension of said pinstripe is 0.0005 mm.

31. The product with color latent images of claim 21, wherein the elements have a longitudinal depth of 0.01mm to 0.1 mm; the planar dimension of the element is 0.01mm-0.1 mm.

32. The product with color latent images according to claim 21, wherein said elements are linear or hemispherical or conical or jar-shaped or pyramid-shaped or cylindrical or polygonal column-shaped.

33. The product with color latent image according to claim 21, wherein said micro-dots are of a hemispherical type, a conical type, a round-jar type, a pyramidal type, a cylindrical type or a polygonal column type.

34. The product with color latent images of claim 21, wherein said micro-dots are concave or convex.

35. The product with color latent images of claim 21, wherein all the micro-points of the same heavy latent image pattern are located at the same height with respect to the reference plane of the mold body.

36. The product with color latent image of claim 21, wherein the surface of the product is an undulating relief surface having elements protruding from the surface, fine micro-dots broken down by the latent image pattern, and a grating-like stripe structure distributed on the surface of the product.

37. A product having a color latent image according to any one of claims 21 to 36, wherein the color latent image pattern on the surface of the product is 2 to 9 times heavier.